Description:Eleven people are injured and more are feared dead after two buildings collapsed in downtown Rio de Janeiro on Wednesday. Doctor Jose Antonio Diniz said he rushed to the collapse when he heard the news. He helped rescue the doorman, who escaped with minor injuries. The two buildings, located in Brazil's second largest city, collapsed after a large explosion was heard. Twenty storeys and another structure half its size came tumbling down, surrounding the area with dust and debris.(1:43)